Dusting apparatus



1938- R. J. STREIF ET A1. 2,127,275

DUSTING APPARATUS Filed Aug. 51, 1937 Ii LZ INVENTOR5 ROBERT J .STPEIFMILTON 5- EOBEETfiUN THE/2 ATTORNEY Patented Aug. 16, 1938 UNITED STATESPATN'i orrlcs DUSTING APPARATUS Application August 31, 1937, Serial No.161,778

9 Claims. (Cl. 43-147) Our invention relates to apparatus for dustingcrops from an airplane; and the broad object of the invention is toprovide a dust disseminating unit by which the dust is given the desiredlateral and downward flow.

Another object of our invention is to provide adjustable meansforchanging the flow characteristics of the unit.

The invention possesses other objects and fea- 10 tures of advantage,some of which, with the foregoing, will be set forth in the followingdescription of our invention. It is to be understood that we do notlimit ourselves to this disclosure of species of our invention, as wemay adopt varil 5 ant embodiments thereof within the scope of theclaims.

Referring to the drawing:

Figure 1 is a side elevational View, partly in section, showing thedusting apparatus embody- 20 ing our invention; and

Figure 2 is a rear elevational view of the same.

In terms of broad inclusion, the dusting apparatus embodying ourinvention comprises a tube adapted to be' mounted longitudinally of 25an airplane, so that a stream of air may flow through the tube; andmeans are provided for admitting dust into the air stream. The tube isshaped to conform with the lower half section of a Venturi tube, thuseliminating the reduced pressure area along the top of the dischargeopening, and causing all of the dust to be directed laterally anddownwardly. A plate is also adjustably mounted adjacent a trailing edgeof the tube, to further control the flow of dust from the 35 tube.

In greater detail, and referring to the drawing, the dusting apparatusembodying our invention comprises a tube 2 adapted to be mountedlongitudinally on an exterior surface of an 1-0 airplane, such as on theunder side of the fuselage as indicated by the dot and dash line tinFigure 1. The tube so mounted provides a channel for a stream of air,and the dust to be distributed by the apparatus is admitted into the airstream in 5 the tube through a duct 4. Any kind of finely dividedmaterial may be dusted on a crop by means of such apparatus, and whenthe plane flies over a field the discharging dust travels down upon thecrop.

50 The important thing with this type of equipment is to get the dust totravel out in a fan shaped flow which is directed downwardly, notupwardly. Tubes used for this purpose have been ordinary Venturi tubes,and the trouble with these is that the dust is directed upwardly as wellas downwardly. The upwardly dispersed dust travels around the body ofthe plane and even upwardly over the stabilizer in some cases.

Inorder to avoid this, our tube has the shape of the lower .half sectiononly of a Venturi tube. The tube is preferably of rectangular shape, andhas a flat top wall 6; the side walls I and bottom wall 8 being concaveto conform to the lower half section of a Venturi tube. Duct 5 opensinto the tube through the top wall 6, and is positioned so 10 that theinlet is adjacent the throat of the tube. By this shape of tube thereduced pressure area along the upper part of the discharge opening,which is characteristic of the ordinary Venturi tube, is eliminated andthe dust is all directed l5 laterally and downwardly.

In order to further control the discharging dust from the tube, wepreferably provide a plate 9 hingeably connected adjacent the lowertrailing edge of the tube on a cross rod 1 I. This flow control plateextends outwardly as a continuation of the bottom wall 8, and may beadjusted to any desired position with respect to the discharge opening.For purposes of this adjustment a curved rod i2 is fastened to each endof the plate, on a reinforcing bar l3, and the rods are held by suitableclamps l4 fastened to reinforcing bars l6 on the side Walls of the tube.By this arrangement the plate is held in a selected position ofadjustment; and notches i1 provided in the rods and engageable by theclamps insure that the plate is positively held.

The action of this plate is to create a reduced pressure area behind it,thus further reducing the pressure at the lower trailing edge of the 3.tube. This tends to further pull the discharging dust downwardly, andthe extent of this downward directing action depends upon the positionof the plate. Thus in the position shown in Figure 1 the dust isdirected down a certain amount, and if the plate is rotated furtherclockwise the dust will be pulled down a still greater amount. As theplate is adjusted further clockwise the pressure behind it becomesreduced to a point Where there is a violent turbulent or burbling actionimparted to the discharging dust. These varying degrees of reducedpressure at the trailing edge of the tube thus permit an operator toadjust the apparatus to best advantage for disseminating the dust, tocompensate for the different slip stream characteristics of differentplanes and the varying flow characteristics of different dusts.

Furthermore, the adjustable feature of the flow control plate allows itto be set back in line with the bottom wall 8, thereby reducing the dragon the plane when the apparatus is not in operation and the plane isbeing ferried from one job to another. If desired, a control mechanismmay be provided for adjusting the plate 9 by a lever in the pilotscompartment, so that the pilot may change the setting of the plate atany time during flight.

It is further understood that flow control plates similar to plate 9 mayalso be provided along the trailing edges of side walls 1. These sideplates would have the effect of further reducing the pressure at thesides of the discharge opening, thus increasing the lateral dispersementof the dust.

In the dust disseminating tube of our invention the forward end of thetube is preferably flared out to provide a scoop for receiving air. Forthis purpose all the walls may be flared out. In order to keep the topof the tube flat however, we prefer to flare out only the bottom andside walls.

We claim:

1. Dusting apparatus comprising a tube through which a stream of air mayflow, said tube in section having the shape of the lower half of aVenturi tube, and an inlet for admitting dust into said air flow.

2. Dusting apparatus comprising a tube through which a stream of air mayflow, said tube having a flat top wall, the other walls conforming tothe lower half section of a Venturi tube, and an inlet for admittingdust into said air flow.

3. Dusting apparatus comprising a tube through which a stream of air mayflow, said tube having a fiat top wall, the other walls being concave,and an inlet for admitting dust into said air flow.

4. Dusting apparatus comprising a tube through which a stream of air mayflow, an inlet for admitting dust into said air flow, and a flow controlplate adjacent a trailing edge of said tube.

5. Dusting apparatus comprising a tube through which a stream of air mayflow, an inlet for admitting dust into said air flow, and a flow controlplate extending outwardly from a trailing edge of said tube.

6. Dusting apparatus comprising a tube through which a stream of air mayflow, an inlet for admitting dust into said air flow, a flow controlplate adjustably mounted adjacent a trailing edge of said tube, andmeans for holding the plate in a selected position of adjustment.

7. Dusting apparatus comprising a tube through which a stream of air mayflow, an inlet for admitting dust into said air flow, and a flow controlplate pivotally mounted for adjustment adjacent a trailing edge of saidtube.

8. Dusting apparatus comprising a tube through which a stream of air mayflow, an inlet for admitting dust into said air flow, said tube having arectangular discharge opening, and a flow control plate adjacent saidopening. I

9. Dusting apparatus comprising a tube through which a stream of air mayflow, said tube in section having the shape of the lower half of aVenturi tube, an inlet for admitting dust into said air flow, and a fioWcontrol plate adjacent a trailing edge of said tube.

ROBERT J. STREIF. MILTON S. ROBERTSON.

